From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: Re: [PATCH 0/3] ensure unique i_ino in filesystems without permanent inode numbers (introduction) Date: Fri, 15 Dec 2006 10:01:03 -0500 Message-ID: <4582B8AF.9060707@redhat.com> References: <457891E7.10902@redhat.com> <45829D94.1090304@redhat.com> <20061215140057.GF30508@lazybastard.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: akpm@osdl.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Christoph Hellwig Return-path: Received: from mx1.redhat.com ([66.187.233.31]:55096 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752700AbWLOPBX (ORCPT ); Fri, 15 Dec 2006 10:01:23 -0500 To: =?UTF-8?B?SsO2cm4gRW5nZWw=?= In-Reply-To: <20061215140057.GF30508@lazybastard.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org J=C3=B6rn Engel wrote: > On Fri, 15 December 2006 08:05:24 -0500, Jeff Layton wrote: >> Jeff Layton wrote: >>> Apologies for the long email, but I couldn't come up with a way to= explain >>> this in fewer words. Many filesystems that are part of the linux k= ernel >>> have problems with how they have assign out i_ino values: >>> >> If there are no further comments/suggestions on this patchset, I'd = like to >> ask Andrew to add it to -mm soon and target getting it rolled into = 2.6.21. > > I'm still unsure whether idr has a sufficient advantage over simply > hashing the inodes. Hch has suggested that keeping the hashtable > smaller is good for performance. But idr adds new complexity, which > should be avoided on its own right. So is the performance benefit b= ig > enough to add more complexity? Is it even measurable? > > J=C3=B6rn > A very good question. Certainly, just hashing them would be a heck of a lot simpler. That was my first inclination when I looked at this, but a= s you said, HCH NAK'ed that idea stating that it would bloat out the hashtable. I tend to think that it's probably not that significant, but that might very much depend on workload. I'm OK with either approach, though I'd like to have some sort of buyin from Christoph on hashing the inodes before I start working on patches = to do that. Christoph, care to comment? -- Jeff - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel= " in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html